Business Communications Systems Research Articles

Quality and Productivity in Injection Mold Tool Construction: A View From Manufacturing

In today's consumer electronics market, being first to the marketplace is paramount to success. The need for early entry into the market has its origin in the rapid evolution of the electronics industry. The saying “It's obsolete by the time you get it home” suggests the desire that drives consumers back to the marketplace for the products with the latest features. Early entry into the market can mean the difference between financial success or failure of any electronic customer premises product. It is generally recognized that the first six months in the life cycle of a low-end consumer product can represent 50 percent of the product's opportunity for return on investment. The Shreveport plant's tooling efforts extend throughout AT&T. Tooling is provided for the Consumer Products, General Business Systems, Business Communications Systems, and Network Products business units. These divisions are all involved with customer premises terminals that have product life cycles of one to four years.

Synchronization in Intelligent Digital Networks

Customer expectations regarding the performance of intelligent digital networks can be met only if careful consideration is given to synchronization at every level in the network. This includes synchronization of the public switched and private networks, and performance of the clocks that control customer premises equipment (CPE). Poor synchronization planning at the public or private network level, as well as poor CPE clock performance can degrade customer applications such as video, facsimile, digital data, encryption, voice-band data, and voice transmission. In this paper, we consider the synchronization philosophies and implementation of both AT&T's national telecommunications network and private customer-owned networks. We will also discuss the performance of typical CPE clocking systems and describe the synchronization systems used in AT&T's line of Definity® business communications systems.

Object oriented system supporting dynamic configuration

The software architecture for a modern business communication system is presented. The main requirements lay in the area of flexibility with respect to configuration and topology. To meet those, a hierarchy of virtual machines is adopted. The top level machine supports an object oriented application layer. The object oriented architecture permits to express very complex relations between objects and agents at the functional layer. Mechanisms located at the lower levels cope with changes in the system configuration. Migration of objects and adaptive routing optimize the systems operation in a given environment.

16 Kb/s high quality voice encoding for satellite communication networks

AbstractThis paper describes applications of adaptive predictive coding (APC) with maximum likelihood quantization (MLQ) which can cover a wide range of coding rates from 4.8 to 16 kb/s for low C/N satellite communication systems, such as maritime, aeronautical mobile and thin‐route satellite communication systems, and also for speech and data integration, including digital circuit multiplication equipment (DCME) in business communication systems, such as INTELSAT business services (IBS). A 16 kb/s APC–MLQ hardware codec has been implemented by NEC–7720 DSP chips and the performance has been confirmed in subjective quality of speech through conversational tests. The objective performance has also been evaluated for non‐voice signals, such as single and multi‐frequency tones, and 1200 and 2400 b/s voiceband data signals. The APC‐MLQ codec can transmit the voice‐band data at 1200 b/s over two asynchronous tandem links and at 2400 b/s over one link. It was noted that the APC‐MLQ codec is superior in speech performance at 16 kb/s to a narrow‐band companded FM and meets requirements for low C/N satellite communication systems. For voice and data integration into 16 kb/s for 64 kb/s links, we propose a multi‐media multiplexing for low C/N digital satellite communication systems and also a small‐scale circuit multiplication system for business use. In these systems, a variable rate coding of APC‐MLQ from 4.8 to 16 kb/s can be effectively introduced for voice and data integration.

Transmission and Retrieval of Information: Statements and Hypotheses for Research

The impact of technology on communication is reviewed. Four general variables relating to business communication systems and communication technology are analyzed: channeling which involves the direction, route, and destination of information; timing which includes the time factor between message receipt and transmission; editing which considers message modification; and abstracting which concerns summarizing major points of a message. Fourteen statements that relate to information transmission and retrieval for each of these variables and their corresponding needed areas of research are presented. These statements will enable business communicators to understand better the relationship between communication technology and business communication systems for future research considerations.

Plastics for housings and functional components

Introduction The impact of silicon technology is now being seen in all aspects of the telecommunications industry from main exchanges to private systems and from telephones to transmission equipment. The advent of the digital exchange based on computer technology has produced customer installations with switching and computing power far greater than is needed to provide facilities equivalent to the older electromechanical systems. One important consequence has been the development of systems leading to the automated office and on a wider basis integrated business information systems. The system may be self contained or may involve a computer based private exchange which in addition to the traditional function will link and process information from many sources; the factory floor, office systems, data processing centres etc., and the hardware may involve dedicated work stations, specialised telephones, VDU's, telex and facsimile machines, data storage facilities, word processors and so on. The change in technology has been accompanied by a significant increase in the plastics content of the equipment. The hub of a business communication system is likely to be the business's P.A.B.X. and if the full potential is to be realised this will be a digital electronic system which will contain a much higher proportion of organic material than electromechanical equipment. If the usage of plastics is compared in Strowger, Crossbar and Electronic equipment a general increase is found in the order of 20 : 40 : 60% of the total material content, by volume of the system; this includes plastic mouldings, wire and cable insulation and printed circuit board and component materials. The explosion in the capacity for processing information has been accompanied by remarkable reduction in equipment size and the trend for miniaturisation is continuing. The total material content of new systems is therefore significantly reduced. For example, the Strowger equipment providing 200 lines would occupy a room, equivalent Crossbar equipment would be half that size, reedelectronics would occupy one cabinet, digital equipment one shelf and the ultimate development in large scale integration would be contained on one chip.

Economical line filtering for business communication systems

Economical active realizations of low-Q, all-pole, low-pass transfer functions are presented. The realizations allow a unidirectional sequence of functional tuning by trimming only resistors. Also, they have low sensitivities to the passive element variations. Experimental results verified the ease of tuning, the low sensitivity, and the low dependence on temperature and power supply variations.